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Star Gazer is the world's only weekly television series on naked eye astronomy. Each weekly episode features selected objects for naked eye viewing for the following week. This video podcast contains the 10 most recent episodes of Jack Horkheimer: Star Gazer.

NASA-supported researchers have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism, which lives in California's Mono Lake, substitutes arsenic for phosphorus in the backbone of its DNA.

Some of the comets in our Solar System probably came from other stars, according to new research by NASA-supported scientists. Studying these 'alien' comets, they say, could reveal new information about stellar systems far, far away.

NASA's Hubble Space Telescope has captured rare images of a suspected asteroid collision. The snapshots show a bizarre X-shaped object at the head of a comet-like trail of material. Their findings will be published in the Oct. 14th issue of Nature.

The Moon cruises past the heart of the lion tonight. Regulus, the brightest star of Leo, stands above the Moon in early evening. The lion’s body trails off to the lower left of Regulus. It ends at the star Denebola — the tip of the lion’s tail.

Denebola is almost twice as big and heavy as the Sun, and about a dozen times brighter. And it’s pretty young as stars go — about one-tenth as old as the Sun.

Like a few other stars in its age and size range, Denebola is encircled by a broad disk of dust. Some of the tiny particles that make up the disk probably are left over from the cloud that gave birth to the star, while others may be debris from collisions between larger chunks of material — the size of asteroids or bigger.

No one has detected planets amidst this debris. But astronomers have found gaps in the disk that could have been cleared out by the gravity of orbiting planets. If planets do exist, they probably formed as the dust grains stuck together to form bigger and bigger bodies — the same way our own Earth took shape.

New planet-hunting instruments could someday snap pictures that are sharp enough to actually see planets around Denebola — worlds orbiting the lion’s tail.

Denebola is at the lower left of the triangle of stars that forms the lion’s hindquarters. It’s among the few dozen brightest stars in the night sky, so it’s easy to find even through the glare of the nearby Moon.

Script by Damond Benningfield, Copyright 2015

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

The life of a close binary system is a matter of give and take. Gas can be siphoned from one star to the other — an act that can radically change both stars.

An example is Regulus, which is the brightest star of Leo, the lion. It stands to the lower left of the Moon at nightfall.

Regulus consists of two pairs of stars. The members of one pair are small and faint. But the other pair is much more intriguing. It consists of the bright star that we see as Regulus, plus the dead core of a star that was once much brighter than Regulus itself.

Originally, this star was the more massive member of the duo, so it aged much faster. As it neared the end of its life, its outer layers of gas puffed up to giant proportions. In fact, they got so puffy that the star couldn’t hold on to them. The gravity of the other star pulled some of the gas off its surface.

As the gas fell onto the less-massive star, it transferred momentum from one star to the other. That made the star that was taking the gas spin much faster. So today, Regulus spins so fast that it bulges outward at its equator.

The process of funneling gas from one star to the other also changed the fate of the now-dead star. It lost so much gas that its corpse — a white dwarf — is much smaller than it otherwise would have been. So while one star in this famous system became bigger and brighter, the other dwindled away to almost nothing.

We’ll talk about another star in Leo tomorrow.

Script by Damond Benningfield, Copyright 2015

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

A giant lake of molten rock forms a dark horseshoe on the surface of Io, one of the big moons of Jupiter, in this view from the Galileo spacecraft. Io is the most volcanically active body in the solar system. Loki Patera (just below center) is the largest of its volcanic features — a lake that covers about 7,000 square miles. Fresh lava bubbles up from below to fill its basin. [NASA/JPL]

A giant lake spreads across the surface of Io, one of the big moons of Jupiter. You wouldn’t want to take a dip in it, though — it’s a pool of molten rock that sizzles at up to 2,000 degrees Fahrenheit.

Io is about the same size as our own moon. But while the Moon is almost completely dead, Io is the most volcanically active body in the solar system. It’s heated by a gravitational tug-of-war between Jupiter and some of its other big moons. This conflict pulls and twists Io’s interior, melting some of its rock. Some of the molten rock pushes its way to the surface through volcanic mountains and lava lakes.

Loki Patera is the largest of these volcanic features — a lake that covers about 7,000 square miles. Fresh lava bubbles up from below to fill its basin, which is shaped like a horseshoe.

Over time, lava at the top of the lake cools and hardens to form a crust, so Loki Patera fades. But the crust is heavier than the molten rock below it, so it sinks, letting the hot lava rise to the surface.

Loki Patera was especially active through much of 2013. It faded in September of that year, but brightened again in October of last year — indicating that lava was once again bubbling to the surface of this giant hot tub.

And Jupiter is quite close to our own moon tonight. The planet looks like a brilliant star close to the upper left of the Moon at nightfall.

Script by Damond Benningfield, Copyright 2015

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

The gibbous Moon passes through the middle of a triangle of bright astronomical objects tonight: the planet Jupiter, the star Procyon, and the “twins” of Gemini.

The brightest point of the triangle is Jupiter, which is to the left of the Moon as darkness falls. Only the Moon and the planet Venus outshine it, so it’s easy to find.

Jupiter shines so brightly because it’s the biggest planet in the solar system — about 11 times wider than Earth. And it’s wrapped in clouds that reflect about half of the sunlight that strikes them back out into space — giving this hefty planet a hefty appearance in the night sky.

Procyon is the second-brightest member of the triangle, standing below the Moon. It’s the leading light of Canis Minor, the little dog. It’s only about 11 light-years away, which makes it one of our closer stellar neighbors. It’s actually two stars — the bright one that’s visible to the eye alone, and a “dead” companion that’s visible only through a telescope.

The triangle’s final point is above the Moon. We’re stretching things a bit, because it actually consists of two stars: Pollux and Castor, the twins of Gemini. Pollux is closer to the Moon, and it’s also the brighter of the two.

Pollux is a cool, bloated star that’s nearing the end of its life. And Castor is a system of six stars or more, although their light blurs together to make a single pinpoint — one of the bright lights that surround the Moon tonight.

Script by Damond Benningfield, Copyright 2015

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

ESOcast is a video podcast series dedicated to bringing you the latest news and research from ESO, the European Southern Observatory. Here we explore the Universe's ultimate frontier with our host Doctor J, a.k.a. Dr. Joe Liske.

The MUSE instrument on ESO’s Very Large Telescope has given astronomers the best ever three-dimensional view of the deep Universe. After staring at the Hubble Deep Field South region for a total of 27 hours the new observations reveal the distances, motions and other properties of far more galaxies than ever before in this tiny piece of the sky. But they also go beyond Hubble and reveal many previously unseen objects.

The European Extremely Large Telescope, or E-ELT for short, will be by far the largest optical and near-infrared telescope in the world. In early December 2014 the ESO Council gave the go-ahead for the first construction phase of the telescope.

High-definition (HD) videos from NASA's Jet Propulsion Laboratory feature the latest news on space and science findings from JPL and NASA. Topics include discoveries made by spacecraft studying planets in our solar system, including Mars, Saturn and our home planet, Earth. Missions also study stars and galaxies in our universe.